August 26, 2015

The authors of an editorial appearing in Open Heart are calling for an end to ‘calorie counting’, instead suggesting a shift towards shaping the diet around the nutritional value of foods in order to reduce risk of cardiovascular disease.

“This review from Malhotra and colleagues of the protective role of a Mediterranean-style diet on the incidence of cardiovascular disease (heart disease, and stroke) presents a headline review of selected nutritional research, reminding readers of its long established health benefits. Benefits that today form the basis of healthy eating guidelines promoted by government, the NHS, and charities such as the Stroke Association and the British Heart Foundation.

“The Mediterranean style of eating doesn’t have one prescriptive dietary pattern in contrast to, say, a low carbohydrate or low fat diet. Nor does it fetish about the inclusion or exclusion of a particular food as being key to its benefit. But it does have common features – however interpreted – with an emphasis on plant based foods such as wholegrains, fruits and vegetables, beans, seeds, fish, mono-unsaturated oils (such as olive oil or rapeseed), and less emphasis on meat and dairy products. It even includes some alcohol.

“This relaxed approach to a varied diet has two key benefits. The first? It’s proven to be easier to follow long term compared to other dietary fads – always important for ongoing good health. The second? The wide range of foods provides bioactive food substances (such as fibres and non-nutrient anti-oxidants like lycopene, flavonoids, and polyphenols) that act synergistically with nutrients in our food yielding additional health benefits. It’s often said that healthwise, the Mediterranean-style diet adds health benefits ‘more than the sum of its constituent parts’.

“So it is disappointing that this incomplete review reduces the diet to mere prescriptive nutrition: eat flaxseeds (good), eat almonds (good), eat olive oil (good), don’t eat sugar (bad) – dogma that’s exactly the opposite to the Mediterranean-style eating approach. The impression to ‘never mind the calories, feel their nutritional quality’ is in my opinion a misleading and superficial approach to a healthy eating. We know that an overweight person following this style of eating can cushion themselves against the risk of some chronic health conditions, but this protection is lost as BMI rises above 27.8 (high end overweight). To imply otherwise is wrong. As a dietitian I prefer the ‘Goldilocks approach’ to all foods ‘Not too much, not too little, just right’. Using that theme, the bowl of fibre rich porridge is part of that Mediterranean style of eating, counting as a wholegrain alternative to wholegrain breads, pasta, or rice.

“One particular point of the review requires clarifying: the PREDIMED study – a study comparing a lower fat diet with two versions of a Mediterranean-style diet (one with added nuts, one with added extra-virgin olive oil) is cited by the authors as ‘reducing the incidence of heart attack and stroke’. It didn’t. The study diet only reduced the incidence of stroke – in itself an important finding. It didn’t (as stated in this article) significantly reduce the risk of heart attack, nor reduce risk of death from cardiovascular disease. Another point omitted from the review was that significant health benefits from PREDIMED were confined to those over 70, and those with pre-existing high blood pressure, diabetes, high blood cholesterol, or obesity – those with a predisposition to cardiovascular disease. In fact, dietary analysis showed that at the end of 5 years the main difference between the PREDIMED study groups was not the use of olive oil or nuts, but a 20% higher fruit and vegetable intake. These changes would have increased soluble fibre, potassium, magnesium and trace element intake, all of which help manage these diseases of ageing that contribute to cardiovascular disease.

“The bottom line? All calories count, whether consumed from foods with a ‘health halo’ (such as extra virgin olive oil), or not. Just as you can’t outrun a bad diet, nor can you out-eat obesity risks with a particular diet.”

“This opinion piece is a reminder that people, and clinicians advising patients, should focus on their whole diet. But with around a quarter of adults in the UK already classed as obese and more than a third overweight, our energy intake does still need to be considered.

“We have known for some time that the traditional Mediterranean diet is associated with a lower risk of heart and circulatory disease and is a simple way of explaining how to eat in a heart healthy way. Without counting the calories in every mouthful, simple swaps like choosing fruit and vegetables rather than fatty and sugary snacks, or water instead of a sugary soft drink, can help to reduce our energy consumption and enable us to reap the benefits to our waistlines as well as consuming a nutritious diet that is beneficial for our overall health.

“It’s also important to stress that people who are a healthy weight can develop risk factors that increase their risk of a heart attack or stroke such as raised cholesterol levels and high blood pressure, so we all need to take care over the food we eat. Whether we are trying to lose weight or not we shouldn’t focus only on the number of calories we consume but our diet as a whole.”

Ms Gaynor Bussell, freelance dietitian specialising in weight management and member of the British Dietetic Association, said:

“I can agree with only one point made in this rather confusing editorial which seems to jump from one poorly proven hypothesis to another, undoing the work of thousands of good quality research papers and backed by years of careful research.

“I do agree that the evidence for a Mediterranean type diet is growing for being protective against heart disease and other diseases – olive oil, not too much red meat and low in saturated fats.

“However, through my training and reading of the evidence as a dietitian dealing with obesity for most of my over 30 year career, I believe that obesity itself is a pro-inflammatory condition and that in order to reduce the burden of cardiovascular disease it needs to be tackled. The answer is to promote a healthy diet, the Mediterranean diet being an example of a healthy diet, AND to reduce obesity.

“This paper touches on other subjects too – so a low carb diet is offered up as a healthy diet whereas the research is again coming down on the side of lower fat being more healthy. Dieticians also agree that trans fats are not good but the level of trans fats in the UK diet has been now shown to be below the level of concern which is set at 2%. In fact in the UK adults have only 0.7 % on average thanks to the fact that most margarines and spreads do not now use trans fat in their manufacture.

“I would argue that both quality and quantity in the diet is important. Weight loss can happen without losing out on diet quality, especially if done based on a healthy diet, not cutting out major food groups (such a carbs) and at a rate of no more than 1-2 lbs a week.”

“In my opinion, it is idiotic to suggest that calories don’t count and then advocate a high fat diet. The editorial has muddled obesity prevention with cardiovascular disease prevention. Obesity is only prevented if energy intake is balanced by energy expenditure. Even a healthy dietary pattern can result in weight gain if too many calories are consumed. For example, the Mediterranean diet of Greece is often used to portray a heart healthy diet. But Greece now has one of the highest rates of obesity in Europe (29% of men) according to the World Obesity Organization, and rates of cardiovascular disease are 20% and 50% higher in men and women than in the UK (Nichols et al. 2014): in 2012 age standardised rates of cardiovascular mortality were 247/100,000 for Greek men and 195/100,000 for women versus 205/100,000 and 29/100,000 in British men and women. The current Greek diet supplies about 46% energy from fat, which is much higher than the 30-35% energy provided by the Mediterranean diet in the past.

“Adding fat to food is the easiest way to increase calories in food so pouring large amounts of olive oil over food or eating loads of nuts is not going to help prevent obesity! Dietary advice to reduce fat intake also helps prevent weight gain (Hooper et al. 2012). Typically, this involves advice to select lean cuts of meat, to avoid fatty meat products, to choose reduced fat dairy products and to minimize the additions of fat to food. Dietary advice to cut carbohydrate intake can often be more effective in controlling weight as it normally accounts for 45-50% of energy intake but also because many fattening foods such as cakes, pastries, biscuits, chocolate, and crisps are a mixture of fat and carbohydrate.

“I think that the editorial is also misleading in suggesting that current dietary advice for cardiovascular disease prevention is a low fat diet (low fat diets typically contain less than 15% energy from fat). In the USA, the main cardioprotective diet is called the Therapeutic Lifestyle Change which encourages increased fruit and vegetable consumption, increased fibre intake from wholegrains and replacement of saturated and trans fatty acids with monounsaturated and polyunsaturated fatty acids, with a range of intakes of fat from 25-35% energy – this is still quite a lot of fat. In the UK, advice is based on that given by Scientific Advisory Committee on Nutrition – which again focuses on promoting a healthy dietary pattern (Reidlinger et al. 2015) not dissimilar to a Mediterranean diet. This includes dietary advice to reduce the intakes of salt, sugar and fat (to no more than 35% energy) especially from meat and dairy foods, and to partially replace the saturated fat using oils high in monounsaturated fatty acids, to increase the consumption of oily fish to at least one serving per week and to consume five portions of fruit and vegetables a day. Current dietary guidelines in both the USA and UK also stress the need to balance energy intake with energy expenditure.

“Good progress has been made in reducing cardiovascular disease (a fall of about 55% in the last decade), which may in part reflect changes in the composition of the food supply. However, we have failed to stem the rise in obesity, particularly in lower socioeconomic groups, and the consequential increase in type 2 diabetes. The bottom line is that those who are getting fat need to eat fewer calories while maintaining a healthy dietary pattern and engage in more physical activity. The challenge is how to persuade those who are not health conscious to change their habits.”

“I am a little concerned that this editorial presents a false choice between calorie counting and nutritional value, when it is possible to do both. However, I agree the main focus should be on what, rather than how much, we eat, particularly when the aim is to reduce heart disease.

“There is good evidence that the Mediterranean diet used in a trial called the PREDIMED study (high in olive oil and nuts) reduces the risk of heart disease, and I recommend this diet to my patients. I do not recommend expensive dietary supplements such as omega-3 fatty acids (the authors quote a study showing this reduced mortality after a heart attack, but other studies have found little or no effect) but instead eating foods naturally high in omega-3 fatty acid (such as oily fish).

“It is now also becoming apparent that excess carbohydrate (particularly sugar) may be more harmful than was previously recognised, although the exact constitution of the ‘perfect’ diet remains unclear.”

‘It is time to stop counting calories, and time instead to promote dietary changes that substantially and rapidly reduce cardiovascular morbidity and mortality’ by Aseem Malhotra et al., published in Open Heart on Wednesday 26 August 2015.

Declared interests

Ms Gaynor Bussell is a freelance dietician; she also works partly for the NHS as a Weight Management Dietitian.

Prof Tom Sanders: is a Scientific Governor of the charity British Nutrition Foundation, member of the scientific advisory committee of the Natural Hydration Council (which promotes the drinking of water), and honorary Nutritional Director of the charity HEART UK. Prof Tom Sanders is now emeritus but when he was doing research at King’ College London, the following applied: Tom does not hold any grants or have any consultancies with companies involved in the production or marketing of sugar-sweetened drinks. In reference to previous funding to Tom’s institution: £4.5 million was donated to King’s College London by Tate & Lyle in 2006; this funding finished in 2011. This money was given to the College and was in recognition of the discovery of the artificial sweetener sucralose by Prof Hough at the Queen Elizabeth College (QEC), which merged with King’s College London. The Tate & Lyle grant paid for the Clinical Research Centre at St Thomas’ that is run by the Guy’s & St Thomas’ Trust, it was not used to fund research on sugar. Tate & Lyle sold their sugar interests to American Sugar so the brand Tate & Lyle still exists but it is no longer linked to the company Tate & Lyle PLC, which gave the money to King’s College London in 2006. Tom also used to work for Ajinomoto on aspartame about 8 years ago.